htaccess rewrite only if request uri is empty - php

Question

My current .htaccess is as follow:
##FOR DUAL LEVEL TIER SUBDOMAIN
#SUBDOMAIN REWRITE for COUNTRY.CATEGORY.uqloo.com
RewriteCond %{HTTP_HOST} !www.mydomain.com$ [NC] # Presuming you don't want to do www
RewriteCond %{HTTP_HOST} ^(.*)\.(.*)\.mydomain\.com [NC] # Catch subdomain
RewriteCond %{REQUEST_URI} !\.(?:jpe?g|png|gif|bmp|php)$ [NC]
RewriteRule ^(.*)$ index.php?sub1=%1&sub2=%2 [QSA,L]
##FOR SINGLE LEVEL TIER SUBDOMAIN
RewriteCond %{HTTP_HOST} !www.mydomain.com$ [NC] # Presuming you don't want to do www
RewriteCond %{HTTP_HOST} ^(.*)\.mydomain\.com [NC] # Catch subdomain
RewriteCond %{REQUEST_URI} !\.(?:jpe?g|png|gif|bmp|php)$ [NC]
RewriteCond %{REQUEST_URI} !^cat/([A-Za-z0-9-]+)?$ [NC] # Don't rewrite if we already have
RewriteRule ^(.*)$ index.php?sub1=%1 [QSA,L]
I'm trying to do single and dual level subdomain redirect only while keeping all my other rewrites for the URI parts relevant. I want to keep the parameters for subdomain relevant as well for the URI rewrites.
An example will be the following rule keeps getting redirected back to index.php when it should go to pages/details.php with parameters sub1 and sub2 available if the subdomain is present.
RewriteRule ^([0-9-]+)?/([A-Za-z0-9-]+)?$
pages/details.php?adid=$1&alias=$2 [NC,L]

Answer 1

You can use these rules:
RewriteEngine On
# pages URL handlers
RewriteCond %{HTTP_HOST} ^(?!www\.)([^.]+)\.mydomain\.com$ [NC]
RewriteRule ^([0-9-]+)/([a-z0-9-]+)/?$ pages/details.php?sub1=%1&adid=$1&alias=$2 [NC,L,QSA]
RewriteCond %{HTTP_HOST} ^(?!www\.)([^.]+)\.([^.]+)\.mydomain\.com$ [NC]
RewriteRule ^([0-9-]+)/([a-z0-9-]+)/?$ pages/details.php?sub1=%1&sub2=%2&adid=$1&alias=$2 [NC,L,QSA]
# subdomain rewrites
RewriteCond %{REQUEST_URI} !\.(?:jpe?g|png|gif|bmp|php)$ [NC]
RewriteCond %{REQUEST_URI} !^/cat/([A-Za-z0-9-]+)?$ [NC]
RewriteCond %{HTTP_HOST} ^(?!www\.)([^.]+)\.mydomain\.com$ [NC]
RewriteRule ^ index.php?sub1=%1 [QSA,L]
RewriteCond %{REQUEST_URI} !\.(?:jpe?g|png|gif|bmp|php)$ [NC]
RewriteCond %{HTTP_HOST} ^(?!www\.)([^.]+)\.([^.]+)\.mydomain\.com$ [NC]
RewriteRule ^ index.php?sub1=%1&sub2=%2 [QSA,L]